Inkjet and laser printers have become commonplace equipment in most workplace and home computing environments. Today, many printers are multi-functional assemblies capable of printing on a large array of print media including letterhead, paper envelopes and labels A recent innovation in the printing industry involves the manufacturing of print media with embedded radio frequency signatures in the form of Radio Frequency identification (RFID) transponders or tags. These tags, sometimes called “Smart Labels”, may be used with a variety of existing printing methods.
Embedded print media generally comprises a backing material (sometimes referred to as the “web”) upon which a label is applied, with a RFID tag sandwiched in between the label and the backing material. There may be one or more labels on the web and the sheet, as presented, may be part label and part plain paper. In some cases, there may be more than one tag arrayed across the width and down the length of the media such that multiple columns and/or rows of tags are contained on the print media.
Another similar type of embedded print media is known as “Smart Paper” in which RFID tags are embedded into the media without labels. One application for Smart Paper is in the area of secure document storage where access to information printed on a document is controlled by use of data control mechanisms such as an Access Control List (“ACL”) embedded in a tag on the media. To control access, a radio frequency reader/programmer situated near a control point, such as an access control cabinet, can check the ID of a user wanting to access the cabinet against the ACL on the tag on the media. If the ID of the user and the ACL do not match, an alarm can be invoked to notify of an attempted breach in security. In addition, the information on the ACL can be spread among a plurality of tags on a single sheet of print media to accommodate multiple accesses by multiple users and to save costs in the printed media.
Printing labels on a cut-sheet printer such as a laser or inkjet printer provides a relatively wide format that allows multiple columns of labels to be used. The use of multiple columns improves the overall rate at which the labels can be printed. At the same time, because the customer can print more than one label for each sheet printed, the relative cost of each label is greatly reduced.
Accordingly, printing on media with embedded RFID tags is rapidly becoming a growing area of label printing. Each tag on a sheet can be printed with certain data, and the RFID tag within that media can be used to allow individualized processing of user associated data. For example, a shipping label might have the delivery address and a package tracking ID printed on it, while the corresponding tag would be programmed with the same information. The delivery information can then be read from the tag, whether or not the package is positioned so that the tag is visible.
Printing label media with RFID tags presents the additional problem of how to manage media with tags that have been damaged or are otherwise inoperable. While it is relatively straightforward to visually examine a printed page and detect gross defects with the printed output, a “bad” tag may be difficult or impossible to distinguish from a “good” tag without attempting to electronically read and verify the tag's operation and content.
Laser printers have a characteristic that may also make the detection and separation of media having defective tags a problem. With laser printers the page typically can not be stopped or reversed during the printing operation without jeopardizing the quality of the printed image on the page. This may make it difficult to distinguish bad tags from good ones without stopping the printing process. Moreover, changing the existing communications protocol between engine and software, or providing additional signals to the options may require substantial modifications in either hardware or software.